Air by-pass or surge control for supercharged internal-combustion engines



July 27, 1954 U 2,684,569

AIR BY-PASS 0R SURGE CONTROL FOR SUPERCHARGED INTERNAL-COMBUSTION ENGINES Original Filed March 5, 1947 2' Sheets-Sheet l FlG.l

INVENTOR ALFRED BUCHI ATTORNEY -A. BUCHI AIR BY-PASS OR SURGE CONTROL FOR SUPERCHARGED INTERNAL-COMBUSTION ENGINES 1947 July 27,1954

2 Sheets-Sheet 2 Original Filed March 5,

INVENTOE ALFRED aUcm I ATTORNEY Patented July 27, 1954 AIR BY-PASS OR SURGE CONTROL FOR SUPERCHARGED INTERNAL-COMBUS- TION ENGINES Alfred Biichi, Winterthur, Switzerland Original application March 5, 1947, Serial No. 732,640, now Patent No. 2,636,341, dated April 28, 1953. Divided and this application May 19, 1950, Serial No. 170,722

Claims priority, application Switzerland March 12, 1946 My present invention relates to improvements in surge-preventing arrangements on supercharged internal combustion engines comprising a plurality of charging blowers, of the centrifugal and/or axial type, at least one thereof being driven by the engine exhaust gases. Such engines are of the type in which the charging blowers-in accordance with the state of operation of the engine-are cut in or out relative to the air supply, so that at least one thereof delivers directly into the engine. This application is a division of my copending Serial 132,640, filed March 5. 1947, now Patent No. 2,636,341. r

The subject matter of my present invention consists in control gears, riggings or arrangements adaptedto prevent-at any given piping connection of the blower delivery lines with the engine-the occurrence of irregularities (such as hard swallowing, surging or equalling) in the delivery of at least one of the charging blowers. Such controls, which e. g. may comprise devices for blowing off part of the pressure fluid (delivered by the respective blower) into a space of lower pressure or other devices serving for the same purpose, may be adjusted either directly by means of the engine governor or by means of the pressure of a pressure fluid supplied by the engine, such as the exhaust gases, the charging air or the lubricating oil and the like. Such controls also, however, may be operated in common in engines comprising elements (adjus"- able automatically or from the outside) for piping the output from difierent kinds of charging blowers directly to the engine or to the other kind of blower.

In the explanation which follows, I assume that the reader is familiar with charging devices for internal combustion engines such as are the subject of my patent No. 2,296,268, issued September 22, 1942.

Several forms of invention are shown, by way of example, in the accompanying drawings, in which Figs. 1 and 1a show a side elevation of a motor, partly in section through a control rigging,

Fig. 2 is a front view of the motor of Fig. 1, and

Figs. 3 and 4 illustrate other forms in partial sections and partly in elevation.

The internal combustion engine I in Figs. 1 and 2 possesses six cylinders 2-1, a governor 8, and two charging blowers 9 and I0. Blower 9 may be of the radial or axial type, and driven by the engine or independently thereof. Blower 10 also may be of the radial or axial type, and is driven 1 Claim. (Cl. 60-13) by the exhaust turbine H which is fed through the exhaust manifolds l2 and I3.

The control rigging according to my present invention, now, is so adapted thatwhen blower 9, with bypass-valve I5 closed, otherwise would swallow hard or be subjected to surges or squallsgoverner 8, by way of the rigging Hi, 15, opens the circular valve 16, thus opening the de livery space I! of blower 9 to the air-intake struc ture it by way of duct 29. Blower is swallowing hard or surging, e. g., when it is of relatively large capacity, and when the exhaust-turbine driven blower H) were sucking no or only little air. Such latter case, again, may arise upon starting the engine or at low load and/or low speed, in spite of valve 23 being open. The entrance chamber for the charging air to engine I is designated by 231. w 7

Lever 15 may be connected to valve rod 19, either fastly or (as shown in Fig. 1) loosely, so that the latter is actuated by rod It only for opening valve I6, in that, when governor S--with engine I idling-is raised, rod 14 is pushed to the right. Governor 8, therefore, is not instrumental in closing valve 8 6. When governor rod t-with the load on engine I increasing-moves to the left valve it automatically is closed again by the spring 2 I, acting against the spring 2 B.

A handle 22 may be provided on lever iii to permit, when required, of holding open or closing circular valve l 6 independently of governor a.

In the form of invention according to Fig. 3, a circular valve 15' is so built into the delivery line 2 of the exhaust-turbine driven blower I i] as to permit of establishing communication between delivery line 24 and suction line 25 of blower Hi. Valve 16 here again (as in Fig. 1) is actuated by governor B by Way of rigging M, [5, and comprises a guide stem 19', a helical spring 2! tending to push valve I 6' to the left into closing position, and a helical spring 28' tending to push valve 16' to the right into open position. Spring disc 26' is adjustably mounted on stem 19' to permit of adjusting the tension of springs 28 and 2|.

Valve I5 is opened-in accordance with my present invention-when, as seen from Fig. 3, delivery line 24 of blower ill to entrance chamher 281 is closed yet by the valve 21, as shown, but engine 1 and thus also exhaust turbo-blower 50/ l 5, having been started already, is not capable yet of building up sufficient pressure to open valve 2?. If bypass valve 16' were not opened at this stage of operation, blower Ill would swallow hard i. e. be subjected to surges, which condition shall be prevented by means of my present invention.

Fig. 4 shows a form of invention, wherein the by-pass valve I6" is actuated by means of a piston 28" secured to valve stem l9". Piston 28 is pushed to the left, biased by a pressure fluid (charging air, exhaust gases, lubricating oil and;

the like). Valve 16 thus is opened and at least part of the air in delivery space I! ,mayescape through duct 29 into air-intake l8 of blower 9. A wing nut 26" is mounted on the outer end, of stem 19', and is pushed by a spring 2 l to the right, i. e. said spring tends to close valve 16''.

The pressure fluid is supplied through the circular valve 30" into the cylindrical space 3!. In Fig. 4, valve 30' is shown in a position in which the pressure fluid is permitted of flowing from- 32 into space 3|, and which corresponds to the position of lever l shown in full lines. Lever I5" is set, e. g., by a governor (not shown) by means of the rod I4".

In the position of lever l5 shown by dotted lines, the admission of pressure fluid at 32 is closed, and cylinder space 3! is drained through the aperture 33". The pressure of spring 2i" then closes valve IS. The latter is opened again in the same way as described in connection with Fig. 1.

Wherever the term independently driven is employed to describe blower or blowers in the claim, I intend to comprehend a blower or blowers which are not driven byan exhaust gas turbine, but rather, by gearing with the engine shaft, or by some other powered rotating unit, such as an electric motor.

What I claim and desire to secure by Letters Patent is:

In a supercharged internal combustion engine provided with at least one turboblower driven by the exhaust gases of the engine to supply air under pressure to the air intake chamber of the engine, an auxiliary independently driven blower to supply air to said chamber, valve means in the line between the auxiliary blower and the chamber closed in response to pressure in the chamber at high turboblower speeds to direct theair from the auxiliary blower to the intake side of the turboblower, a second valve means between the turboblower and the chamber adapted to close olI the turboblower from the chamber at low turboblower speeds, the combination therewith of control means to prevent surging in the turboblower when closed ofi, comprising a relief valve adjacent the outlet of the turboblower, an-engine speed responsive device and linkage connecting the said device with said relief valve, said device and linkage permitting in response to small pressure air consumption of the internal combustion engine said relief valve to be opened by spring pressure together with the air pressure in said outlet of the turboblower to direct at least part of the air from the turboblower outlet back to the inlet thereof, and to close said relief valve by said device andlinkage at larger air consumptions of the engine,

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,111,498 Rotter Sept. 22, 1914 1,476,418 Rice Dec. 4, 1923 2,196,247 Browne et al Apr. 9, 1940 2,296,268 Biichi Sept. 22, 1942 2,306,277 Oswald Dec. 22, 1942 2,404,324 Staley July 16, 1946 2,466,282 Sparrow et al Apr. 5, 1949 

